The primary outcome parameter of this study was the pain scores. The sample size for the primary variable was calculated based on a standard deviation of 20 mm estimated from a previous study. A power analysis with a type II error of 20% at a two-sided 5% significance level estimated 22 patients per group to be included. Investigators included 26 patients per groups for possible missing date. χ2 test for categorical data and independent samples t-test for the comparison of VAS and WOMAC scores between groups were used for statistical analysis.